1. Field of the Invention
The present invention relates to document processing apparatuses and document processing methods. More specifically, the present invention relates to a document processing apparatus and a document processing method with which input of document data in Postscript (PS) or Portable Document Format (PDF) is received, the content of the document is checked, and then data in an intermediate format for output (intermediate data) is generated.
2. Description of the Related Art
Conventionally, for example, in a printing system that includes a computer and a printer, what is called a preflight check is carried out before an outputting process.
In the preflight check, document data in PS, PDF, or other formats is input, and it is checked whether the document will be output correctly before printing or otherwise outputting the document.
According to the conventional art, however, when a preflight check is carried out, an interpreter (an interpretation process) is run in order to interpret document data. More specifically, the interpreter interprets document data to check whether resources needed for the document are provided in the printing system, and generates intermediate data for output. The intermediate data refers to, for example, data describing objects included in individual bands, i.e., areas of each page as divided by boundaries extending in parallel to a main scanning direction. The objects are described based on a grammar that can be interpreted by, for example, a printer. The intermediate data is sometimes referred to as DLC for short.
However, the intermediate data generated in the preflight check is not used for output. In an outputting process that is executed after completion of the preflight check, the interpreter is run again to generate intermediate data. As described above, the interpreter for processing document data is run twice, i.e., in the preflight check and in the outputting process, generating intermediate data each time. Thus, processing time for generating intermediate data in the preflight check is wasted, and the unneeded process could block or otherwise restrict other processes, so that the processing is not so efficient.
Japanese Patent Laid-Open No. 2001-005620 describes techniques for generating intermediate data. However, a preflight check is not carried out in the techniques. Furthermore, according to the techniques, intermediate data is generated even for data with which a document will not be output correctly, thus the processing could be wasted. Furthermore, according to the techniques, intermediate data is generated for all the pages, so that a large load could be imposed on a machine or the like when the number of pages is large.